1. Field of Invention
The present invention relates to a tow strap and, more particularly, to a tow strap apparatus equipped with a speed-increasing gearbox.
2. Related Prior Art
A vehicle sometimes breaks or gets stuck in the sand, mud or snow. To get such a vehicle out of the trouble, it can be tied to another vehicle via a rope or tow strap. The first vehicle can be towed and rescued by the second vehicle.
A tow strap is often made of woven fabric and made of an adequate length. However, it is troublesome to reel the tow strap when the tow strap is not in use.
As disclosed in U.S. Pat. No. 7,942,360, a conventional tow strap apparatus 10 includes a casing 12, a tow strap 16, a reel 28 and two coil springs 50. The casing 12 includes two opposite apertures 15 defined therein. The tow strap 16 includes two hooks 20 tied to a webbing 18. The reel 28 includes a hub 36 that includes two halves. Teeth 40 are formed on each half of the hub 36. The webbing 18 is inserted through a gap between the halves of the hub 36. The webbing 18 is firmly held onto the hub 36 by the teeth 40. The reel 28 is placed in the casing 12. Each end of the webbing 18 is placed out of the casing 12 through an aperture 15. The hooks 20 are placed out of the casing 12. Each hook 20 is engaged with a vehicle in use. Each coil spring 52 is connected to the casing 12 at an end and connected to the reel 28 at another end. The coil springs 50 are loaded when the webbing 18 is released from the reel 28. The webbing 18 is reeled on the reel 28 by the coil springs 50 when the hooks 20 are detached from the vehicles.
The use of the conventional tow strap apparatus 10 is not without any problem. At first, the webbing 18 is inevitably damaged by the teeth 40 and could be broken into two halves after some time of use. Secondly, the diameter of the coil springs 50 is large as the webbing 18 is long. A large coil spring requires a lot of steel which is heavy and expensive.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.